Diagnostic Test Could Cut Down On Number Of Unnecessary Angioplasty Procedures, Study Shows

DALLAS, July 15 - A readily available, but underused,
diagnostic test could help prevent unnecessary angioplasties,
a procedure used to clean out blocked blood vessels to the
heart, report researchers in today's Circulation, a journal
of the American Heart Association.

Individuals who have chest
pains or other symptoms of this condition, known as coronary
heart disease, often undergo angiography so that doctors can
determine the amount and location of artery blockage and
decide whether treatment is necessary. Angiography provides a
two-dimensional view of the artery and may not reliably
predict whether arterial blood flow is impaired. When blood
flow in the arteries is impaired, a heart attack can occur.

The study's authors recommend that angiography be followed by
another test, called Doppler ultrasound, so that the velocity
of blood flow can be closely measured and the size and
location of arterial blockage can be more accurately
evaluated.

Approximately 420,000 angioplasties are
performed each year in the United States, but, according to
researchers, 70 percent of those are not preceded by a test
documenting ischemia, which is decreased blood flow resulting
from the constriction or obstruction of an artery. Coronary
angiograms alone do not reliably predict whether an
intermediate stenosis -- 40 to 70 percent of the artery is
blocked -- causes significant obstruction.

"You can't say
that all of those angioplasties were unnecessary," Heller
says. "But you can certainly assume that many were done
without evidence for their indication."

In much the same way
that a police officer uses a radar gun to determine how fast
a car is traveling, physicians can use Doppler ultrasound to
get a better idea of the flow rate of blood through the
arteries. A picture of the artery alone may not be enough to
determine the amount of blockage, just as a photo of a
speeding car may not always prove how fast it is going.

Patients enrolled in the study underwent angiography with
Doppler ultrasound and had exercise imaging stress testing,
which provides an indication of ischemia, or decreased blood
flow. The Doppler and imaging data agreed in 46 of 52
blockages (88 percent) in patients achieving their target
heart rate on the stress test.

"Doppler ultrasound promises
to help clarify whether a narrowed artery is causing a
problem, and therefore, should reduce unnecessary
procedures," Heller says. "For those patients who have chest
pain, this technology can also open the door for relief from
symptoms from an arterial narrowing that may not have been
adequately assessed on the angiogram."

With the availability
of Doppler ultrasound and its success, why isn't it more
widely used?

"The major issue is third-party payer
reimbursement, or the lack thereof," Heller said. "There is
now a large body of data that clearly documents the utility
of this test for coronary artery disease, and it's
frustrating to me that third-party payers are not reimbursing
for this vital procedure."

Media advisory: Dr. Heller can be reached at (516) 663-8856.
(Please do not publish telephone numbers.)

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